[英]How can I update a row in a javascript array based on a key value?
我有一個這樣的數據數組:
var nameInfo = [{name: "Moroni", age: 50},
{name: "Tiancum", age: 43},
{name: "Jacob", age: 27},
{name: "Nephi", age: 29},
{name: "Enos", age: 34}];
如果我有這樣的對象:
var nameInfo = {name: "Moroni", age: 51};
有沒有一種簡單的方法可以更新變量nameInfo。 這些之間的關鍵是名稱列。 我知道有一種方法可以通過搜索行,刪除和添加來實現這一點,但我想有辦法在更新行的地方執行此操作。 請注意,如果它有幫助我確實加載了underscore.js.
最簡單的方法是循環查找具有匹配名稱的那個然后更新年齡:
var newNameInfo = {name: "Moroni", age: 51};
var name = newNameInfo.name;
for (var i = 0, l = nameInfo.length; i < l; i++) {
if (nameInfo[i].name === name) {
nameInfo[i].age = newNameInfo.age;
break;
}
}
使用下划線,您可以使用_.find方法執行以下操作而不是for循環:
var match = _.find(nameInfo, function(item) { return item.name === name })
if (match) {
match.age = newNameInfo.age;
}
編輯:您可以使用ES6 過濾器結合箭頭功能
nameInfo.filter(x => {return x.name === nametofind })[0].age = newage
您可以使用_.where
函數
var match = _.where(nameInfo , {name :nametofind });
然后更新比賽
match[0].age = newage
var nameInfo = [{name: "Moroni", age: 50},{name: "Tiancum", age: 43},
{name: "Jacob", age: 27},{name: "Nephi", age: 29},
{name: "Enos", age: 34}
];
_.map(nameInfo, function(obj){
if(obj.name=='Moroni') {
obj.age=51; // Or replace the whole obj
}
});
這應該做到這一點。 它整潔可靠,帶有下划線
使用Underscore,您可以使用_.findWhere http://underscorejs.org/#findWhere
_.findWhere(publicServicePulitzers, {newsroom: "The New York Times"});
=> {year: 1918, newsroom: "The New York Times",
reason: "For its public service in publishing in full so many official reports,
documents and speeches by European statesmen relating to the progress and
conduct of the war."}
您可以使用findWhere和extend
obj = _.findWhere(@songs, {id: id})
_.extend(obj, {name:'foo', age:12});
您可以使用_.find方法,如下所示:
var nameInfos = [{name: "Moroni", age: 50},
{name: "Tiancum", age: 43},
{name: "Jacob", age: 27},
{name: "Nephi", age: 29},
{name: "Enos", age: 34}];
var nameToSearch = "Moroni";
var myRecord = _.find(nameInfos, function(record){ return record.name === nameToSearch; });
工作示例: http : //jsfiddle.net/9C2u3/
var match = _.findWhere(nameInfo , {name :nametofind });
match.age = newage
使用lodash的find()函數的明星前鋒,
var nameInfo = [{name: "Moroni", age: 50},
{name: "Tiancum", age: 43},
{name: "Jacob", age: 27},
{name: "Nephi", age: 29},
{name: "Enos", age: 34}];
var objToUpdate = _.find(nameInfo, {name: "Moroni"});
if(objToUpdate) objToUpdate.age = 51;
console.log(nameInfo); // Moroni age will be 51;
注意:如果有多個Moroni對象,_. find只能獲取第一個匹配項。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.